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.Dd April 29, 2024
.Dt SERVICES 5
.Os
.Sh NAME
.Nm services
.Nd internet service name and port number data base
.Sh DESCRIPTION
The
.Nm
file contains information regarding
the known services available in the
Internet.
For each service a single line should be present
with the following information:
.Bd -unfilled -offset indent
official service name
port number
protocol name
aliases
.Ed
.Pp
Items are separated by any number of blanks and/or tab characters.
The port number and protocol name are considered a single
.Em item ;
a ``/'' is used to
separate the port and protocol (e.g.\& ``512/tcp'').
A ``#'' indicates the beginning of
a comment; subsequent characters up to the end of the line are
not interpreted by the routines which search the file.
.Pp
Service names may contain any printable
character other than a field delimiter, newline,
or comment character.
.Pp
If
.Dq db
is specified as source in the
.Xr nsswitch.conf 5 ,
.Pa /var/db/services.db
is searched.
The database in
.Pa /var/db/services.db
needs to be updated with
.Xr services_mkdb 8
after changes to the services file have been applied.
.Sh NIS INTERACTION
Access to the NIS
.Pa services.byname
map can be enabled by adding a single ``+'' on a line by itself
in the
.Pa /etc/services
file.
This causes the contents of the NIS services map to be inserted
at the location where the ``+'' appears.
.Sh FILES
.Bl -tag -width /etc/services -compact
.It Pa /etc/services
The
.Nm
file resides in
.Pa /etc .
.El
.Sh SEE ALSO
.Xr getservent 3 ,
.Xr nsswitch.conf 5 ,
.Xr services_mkdb 8
.Sh HISTORY
The
.Nm
file format appeared in
.Bx 4.2 .
.Sh BUGS
A name server should be used instead of a static file.
